1. Field of the Invention
The technical field of the present invention is that of lighting and/or signaling devices for automotive vehicles, and more particularly that of optical modules comprising at least one light source and equipped with an optical focusing device.
2. Description of the Related Art
A headlamp fitted to an automotive vehicle conventionally consists of a housing closed by a window thus defining an internal volume in which components are placed, which components act to generate a light beam intended to be projected onto the path traveled by the vehicle.
These components, in particular, include a light source, a cover, the function of which is to hide the mechanical and electrical parts of components that it is desired to conceal from external observation, or an element for generating a cutoff, in the case where the headlamp has a low-beam function.
For a headlamp equipped with a focusing device, the aforementioned components have been observed to degrade. Specifically, the focusing device, the primary function of which is to concentrate the light emitted by the light source with a view to generating a light beam when the headlamp is turned on, also has a tendency to focus solar rays that enter into the lighting and/or signaling device.
Depending on the position of the sun in the sky, there are situations where the focusing device concentrates the solar rays on one or other of the components installed inside the lighting and/or signaling device. More precisely, concentration of solar rays on the light source increases its temperature until the maximum allowable limit of the light source is exceeded. This is also the case as regards the electronic components that are placed near the light source. Such a situation generates a fire risk in the vehicle.
The situation is even more critical for the cutoff generating element because the latter must meet extremely precise tolerances in order to respect standards relating to the definition of a cutoff. It is thus out of the question to use plastics in the presence of a focusing device that concentrates solar rays, because of the risk of burning the cutoff generating element. Thus a metal is used to manufacture this cutoff generating element which, apart from problems of compatibility between the optical module, which is generally made of plastic, and the metal cutoff generating element, has the aforementioned drawbacks.